The present invention is directed to ink compositions and, more specifically, the present invention relates to inks with a melting point of between about 60.degree. C. and about 150.degree. C., and preferably between about 70 to about 90.degree. C. as measured with a differential Scanning Calorimeter (DSC 2910 from TA Instruments) and which inks are especially useful for acoustic ink printing, processes and apparatuses, reference, for example, U.S. Pat. No. 5,121,141, U.S. Pat. No. 5,111,220, U.S. Pat. No. 5,128,726, U.S. Pat. No. 5,371,531, the disclosures of which are totally incorporated herein by reference, including especially acoustic ink processes as illustrated in the above recited copending applications, such as an acoustic ink printer for printing images on a record medium.
The inks of the present invention in embodiments thereof can be referred to as a phase change ink, that is, for example, an ink that changes from a liquid state to solid state in a suitable period of time, for example, from about 1 to about 100 milliseconds and preferably less than about 10, such as from about 2 to about 7 milliseconds (from about to about includes at least all the values and numbers there between), and which ink is comprised of a nonaqueous phase-change color spreading polymeric carbamate compound with a melting point of, for example, lower than, or equal to about 120.degree. C. and preferably between about 60 to about 100.degree. C., (2) a non-aqueous viscosity modifying monomer carbamate compound that can, for example, fill or substantially fill the substrate pores thereof thus enabling, for example, images of uniform gloss, and wherein the substrate is preferably paper with, for example, and which carbamate possesses a boiling point of, for example, higher than about 150.degree. C. (Centigrade), and more specifically, with a boiling point from about 150.degree. C. to about 225.degree. C., and preferably from about 170.degree. C. to about 200.degree. C., and a melting point of, for example, between about 25.degree. C. to about 90.degree. C. and preferably with a low acoustic loss, which enables a reduction, or minimization of energy consumption, and which acoustic loss is in the range of, for example, from about 5 to 60 dB/mm, and preferably between about 5 to about 40 dB/mm; (3) a conductive compound (4) a lightfast compound; (5) and a colorant such as a dye, a pigment or mixtures thereof.
More specifically, the present invention is directed to phase-change acoustic ink compositions comprised of (1) non-aqueous solid phase-change compound, such as poly(vinyl N-octadecyl carbamate) (Aldrich #45,806-6); hardness value 80; poly(vinyl N-arylcarbamate) such as poly(vinyl N-phenyl carbamate), with a melting point of lower than about 140.degree. C. and preferably between about 60.degree. C. and about 100.degree. C., and with a low acoustic loss and which acoustic loss is below about 100 dB/mm, and preferably is in the range of between about 25 to about 80 dB/mm at the jetting temperature; (2) a carbamate compound having a boiling point of higher than about 150.degree. C., and more specifically, having a boiling point of from about 150.degree. C. to about 225.degree. C. and preferably from about 170.degree. C. to about 200.degree. C., and a melting point of less than 90.degree. C. with low acoustic loss, which enables a reduction, or minimization of energy consumption, and which acoustic loss is in the range of from about 5 to 60 dB/mm, and preferably between 5 to 40 dB/mm; (3) a conductive compound (4) a lighffastness compound, and (5) a colorant, and wherein there can be generated with such inks excellent developed images on plain and coated papers with acceptable image permanence, excellent projection efficiency on transparencies without a post fusing step, and excellent crease resistance, and wherein the inks possess acceptable, and in embodiments, superior lightfast, for example, between about 90 to about 100 percent, and superior waterfast values of, for example, between about 95 to about 100 percent. Moreover, in embodiments of the present invention there is enabled the elimination, or minimization of undesirable paper curl since water need not be present, or minimum amounts less than about 1 percent, for example, from about 0.5 to about 0.99 of water may be selected in embodiments, and it is preferred that there be an absence of water. When water is not present in the inks, a dryer can be avoided thereby minimizing the cost of the acoustic ink jet apparatus and process.